Styluses for capacitive touchscreen devices have writing tips made of electrically-conducting material such as conducting foam or conducting rubber. Other conductors such as metal could be used, however a soft material is preferred because metal could damage a touchscreen surface. In one type of passive stylus, the stylus shaft is formed of an electrically-conducting material that transfers charge from a user's hand to the conducting tip. An alternate design (an “active stylus”) may include an external power source (e.g. a battery) to provide additional functionality to the stylus. This functionality may be manifested either by providing additional means of affecting the capacitive touch interaction or by enabling communication with the touch-enabled devices by other means, supplementing the user experience.
Prior art styluses are designed to function anytime the user brings the stylus in contact with a touchscreen surface, independent of how the stylus is gripped in the user's hand. The standard writing grip for a writing instrument is a tripod grip, in which the thumb, index, and middle fingers simultaneously contact the shaft of the writing instrument. Conventional touchscreen styluses do not distinguish between a proper tripod writing grip and an incorrect grip, such as an overhand first grip that a young child may use.